MPEG-1 on DVD with different aspect ratios

[DRP]

Just wondering if this is possible at all? I have been trying, but no luck so far. I have two MPEG-1 files. One needs to be displayed in 16:9 ratio and the other in 4:3. I want to put them both on the same DVD. I have patched the headers of the MPG elementary streams to display in 16:9 & 4:3 respectively and this works just fine when played in MPC. I have authored the DVD with the two files in separate VTS and bridged them together. I have tried patching the resulting VOB files to force the aspect ratio back to 16:9 again after the compile, but when played, they still both display as 4:3.

Anybody know of a way of doing this or is it a lost cause?

[guns1inger]

On Full D1 Mpeg-2 supports aspect ratios on DVD. You have a couple of choices. You can either leave them as-s, and manually change aspect ratios during playback with your TV remote, or resize the 16:9 material to fit into a 4:3 letterboxed frame and re-encode. This will cost you in resolution and detail.

[DB83]

For mpeg-1 I believe your movie will have to be 352*288 (for PAL) whatever the AR. So to get 16:9 I suspect you need to crop and re-encode rataining the 352*288 ratio - 36 pixels top and 36 pixels bottom ie half what you would do for 720*576.

Otherwise, why not convert both to mpeg-2 720*576. Depending on the quality of the original it may be ok and then create the 16:9 from the 720*576 with a 72 pixel top and bottom crop.

[DRP]

Yeah the videos are actually NTSC so 352x240 with a 0.8437 (16:9 525 lines NTSC) aspect ratio header patch on the file to display as 16:9 ratio (or near enough). I was hoping to be able to do with without re-encoding anything. The files are fine for putting on DVD as is apart from the aspect ratio thing.

[jman98]

Be warned that although MPEG-1 video is in the spec for DVD, some DVD players will NOT display it although they are violating the spec by refusing to do so. I have a DVD that I self-authored using Scenarist (if anyone cares) that uses only MPEG-1 video and I sure that it is totally compliant with the specs. I made it from some freely available Star Trek fan episodes that were of very low resolution. I thought it might be interesting to have a test disc. Anyway, my Toshiba HD DVD player absolutely refused to play it and gave me some error message relating to it being MPEG-1. Their HD DVD players did not support MPEG-1.

Note too that many consumer available authoring programs will refuse to author DVDs with MPEG-1 input. They should support it, but some of the cheaper ones do not.

[DRP]

Not a problem here. Using DVD-lab PRO for the authoring and all my players have no qualms about playing MPEG-1 on DVD from past experience.

[El Heggunte]

There are several software/firmware MPEG decoders which "think" MPEG-1 aspect ratio must always be either 4:3 or "1:1" YMMV. Also, VCD resolution (352 x ###) is not "wide enough" for the 16:9 aspect ratio, IMHO.

[Cornucopia]

Here's what I know about the specs:

MPEG1 fully supports different PARs. Good MPEG1 decoders SHOULD respect them.
But that's just "generic" MPEG1.

VCD expects a standard 4:3 DAR. I have been able, however, to patch the MPEG1 System Stream header and successfully author a 16:9 DAR "widescreen" VCD. Problem is that, as mentioned above, SOME decoders don't respect them.

DVD is different. The spec says that the MPEG1 that is allowed on DVD must be 4:3 ONLY. It also must be <=1856kbps and CBR. So the ability to change the DAR, the ability to use VBR, and the wide range of available bitrates are RESERVED for MPEG2. IOW, the MPEG1 that can exist on a DVD is a specific subset of generic MPEG1.

Good try, though.

Scott

[AlanHK]

Well, I've never seen 16:9 MPEG1. but a couple suggestions:

GfD will author using MPEG1 video and MP2 or AC3 audio, sampled at 48000 HZ.

It may not recognise 16:9 video though.
If not, after authoring you could try PGCEdit to change that.

It's outside the spec, as Cornucopia says, but worth a try.

Otherwise, convert to MPEG2.
You can load the MPEG1 in Avisynth and use some cleaning/smoothing/scaling filters, to bring it up to 720x480 (if NTSC) and encode using HCEnc.